Synonyms/Hypernyms (Ordered by Estimated Frequency) of noun ob

2 senses of ob

Sense 1
Ob, Ob River -- (a major river of western Siberia; flows generally northward and westward to the Gulf of Ob and the Kara Sea)
       INSTANCE OF=> river -- (a large natural stream of water (larger than a creek); "the river was navigable for 50 miles")

Sense 2
obstetrics, OB, tocology, midwifery -- (the branch of medicine dealing with childbirth and care of the mother)
       => medicine, medical specialty -- (the branches of medical science that deal with nonsurgical techniques)